the 8048 is from that mini vid sea battle game. On Galaxian, what happens is it's a relaxation oscillator I think, so as pitch decreases, I guess the effective duty cycle would change too. The pulse width doesn't change, but the period between pulses does. i.e. the high time is constant but the low time varies.
And yes, that baseball game is stupidly complicated. The football game I dumped by mattel is also stupidly complicated as well (world champ. football).